Machine Kinematics

Mechanism

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Which of the following statement is correct as regard to the difference between a machine and a structure?
The parts of a machine move relative to one another, whereas the members of a structure do not move relative to one another.
The links of a machine may transmit both power and motion, whereas the members of a structure transmit forces only.
A machine transforms the available energy into some useful work, whereas in a structure no energy is transformed into useful work.
all of the mentioned
Explanation:
None
Question 2
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A point on a connecting link of a double slider crank mechanism traces a
straight line path
hyperbolic path
parabolic path
elliptical path
Explanation:
None.
Question 3
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Whitworth quick return motion mechanism is an inversion of a double slider crank chain.
True
False
Explanation:
Whitworth quick return motion mechanism is a form of single slider crank chain and it consists of one sliding pair and three turning pairs.
Question 4
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If the number of links in a mechanism are equal to l, then the number of possible inversions are equal to
l – 2
l – 1
l
l + 1
Explanation:
Whatever is the number of links in a mechanism, only that much number of inversion can be obtained.
Question 5
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The Grubler’s criterion for determining the degrees of freedom (n) of a mechanism having plane motion is
n = (l – 1) – j
n = 2(l – 1) – 2j
n = 3(l – 1) – 2j
n = 4(l – 1) – 3j
Explanation:
None
Question 6
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The method of obtaining different mechanisms by fixing in turn different links in a kinematic chain, is known as
structure
machine
inversion
compound mechanism
Explanation:
We can obtain as many mechanisms as the number of links in kinematic chain by fixing, in turn,different links in a kinematic chain. This method is known as inversion of the mechanism.
Question 7
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Whitworth quick return motion mechanism consists of three turning pairs and one sliding pair.
True
False
Explanation:
Whitworth quick return motion mechanism is a form of single slider crank chain and it consists of one sliding pair and three turning pairs.
Question 8
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Which of the following is an inversion of a double slider crank chain?
elliptical trammel
scotch yoke mechanism
oldham’s coupling.
All of the mentioned
Explanation:
A double slider crank chain consists of two sliding pairs and two turning pairs. The inversions of a double slider crank chain are as follows:
Question 9
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The inversion of a mechanism is
changing of a higher pair to a lower pair
turning its upside down
obtained by fixing different links in a kinematic chain
obtained by reversing the input and output motion
Explanation:
We can obtain as many mechanisms as the number of links in kinematic chain by fixing, in turn,different links in a kinematic chain. This method is known as inversion of the mechanism.
Question 10
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Pass Ratio : 100%
The mechanism forms a structure, when the number of degrees of freedom (n) is equal to
0
1
2
-1
Explanation:
A structure can be formed only when the number of degrees of freedom is zero.